1. Technical Field
The present invention relates to a projector that modulates illumination light using liquid crystal light valves and projects the modulated image light.
2. Related Art
General projectors according to the related art include a light source that generates substantially white light, an illumination optical system that makes the light emitted from the light source uniform and polarizes the light, a color separation optical system that separates the light passing through the illumination optical system and guides the separated light onto three green, blue, and red optical paths, three liquid crystal panels on which three color illumination light components are incident, a cross dichroic prism that composes images from the three liquid crystal panels, and a projection lens that projects the composed enlarged light.
A projector has been proposed in which the F-number of an illumination optical system is reduced to improve the brightness of light without increasing the size of the illumination optical system. In the projector, a condenser lens is provided between a superimposing lens and a liquid crystal light valve, and telecentricity is obtained by the condenser lens. In this way, it is possible to remove a field lens provided before the liquid crystal light valve (for example, see JP-A-2008-165136).
In addition, a projector has been proposed in which a field lens is provided after a polarizing element in an illumination optical system and a condenser lens is provided before a first dichroic mirror in a color separation optical system (for example, see JP-A-2007-57810).
However, in the projector disclosed in JP-A-2008-165136, the size of the condenser lens tends to be larger than that when the field lens is provided. Therefore, the manufacturing costs of the projector tend to be more than those of a general projector according to the related art.
In the projector disclosed in JP-A-2007-57810, although the number of lenses added is one smaller than that of the projector disclosed in JP-A-2008-165136, a lens superimposing divided light and a lens ensuring telecentricity are individually provided. Therefore, it is difficult to ensure brightness while reducing manufacturing costs.